Exemplary embodiments of the present disclosure relate to a hybrid power generation system, and more particularly, to a hybrid power generation system capable of enhancing efficiency of production of electricity and heating heat by integrated power generation using supercritical carbon dioxide (CO2) and cogeneration.
Internationally, the need to efficiently produce electric power is gradually increasing, and various efforts have been made to reduce generation of pollutants and increase power production. A study on a power generation system using supercritical carbon dioxide (CO2), which utilizes supercritical carbon dioxide as a working fluid is disclosed in Korean Patent Application Publication No. 2013-0036180.
Since the supercritical carbon dioxide simultaneously has a density similar to that of liquid and a viscosity similar to that of gas, it is possible to reduce the size of devices and to reduce the consumption of electric power for compression and circulation of the fluid. In addition, the supercritical carbon dioxide has an advantage in that it is very easy to handle since it has a smaller critical point of 31.4° C. and 72.8 atmospheres, compared to water having a critical point of 373.95° C. and 217.7 atmospheres.
In addition, most power generation systems using supercritical carbon dioxide are operated as a closed cycle that does not discharge carbon dioxide used for power generation to the outside, thereby significantly contributing to a reduction of pollutant discharge for each country.
However, since it is difficult for an existing power generation system using supercritical carbon dioxide to have a certain magnitude or more, the system may supply a portion of necessary electric power. In addition, it is desirable to increase production efficiency of electric power and reduce discharge of pollutants in a coal-fired thermal power generation system.